1. Field of the Invention
The present invention relates to an exhaust device for a vehicle, for example, a motorcycle.
2. Description of Background Art
Conventionally, exhaust devices are known wherein a muffler positioned at a rear portion of an exhaust system extends rearwardly from an engine and is disposed in a rear cowl. In such exhaust devices the rear cowl may be provided with a bulged portion in the left-right direction. The bulged portion is provided with an air guide portion, while the rear cowl is provided with an air exhaust port at a rear portion thereof. In addition, the muffler is disposed along a cooling passage extending from the air guide port to the air exhaust port. See, for example, Japanese Patent Laid-Open No. Hei 4-35989.
The above-mentioned exhaust device makes it possible to efficiently guide a running airflow and thereby to cool the muffler. However, this exhaust device involves a problem in that the bulged portion must be formed in a large size. Therefore, the designing of the vehicle body is greatly restricted.
In view of this problem, in order to suppress the bulging amount in the width direction without varying the volume of the muffler which affects the noise insulation performance, it may be contemplated to extend a rear portion of the muffler to the rear side so as to suppress the bulging of the vehicle body in the vehicle width direction and enhance the degree of freedom in designing, without spoiling the exhaust noise reducing function. If such an approach is adopted, however, the rear portion of the muffler would project out, thereby spoiling the appearance quality.